1. Field of the Invention
This invention pertains to four different methods of heat conversion:
a. Thermophotovoltaic systems PA1 b. Thermionic power generation of the ignited cesium variety, PA1 c. Alkali-metal thermoelectric converters, PA1 d. Methane reformation. PA1 a. Thermophotovoltaic conversion is described in the paper "Improved Thermophotovoltaic Power System" W. E. Horne et al (17th IECEC) utilizing silicon photovoltaic cells, and "Low-Bandgap Thermophotovoltaic System Design" Burger and Ewell (1993 IECEC) utilizing InAs photovoltaic cells. PA1 b. Thermionic power generation is well enough known to be the title of an article in the McGraw-Hill Encyclopedia of Science and Technology. PA1 c. Alkali-metal thermal electric converters are the subject of many papers, such as "Operation of Low Temperature AMTEC Cells" R. K. Sievers et al (1992 IECEC). PA1 d. Methane reformation is described in such as U.S. Pat. No. 4,109,701 to Hilberath et al.
More particularly it relates to the interrelation of these systems in a cogeneration scheme to convert solar energy into electricity. And most especially, it relates to ordering these different methods in descending order of their operating temperatures.
2. Description of the Prior Art
Each method by itself is known to researchers:
Each method has its own art and within each art attempts are well known to unite the method in question to a solar power production cycle. (See e.g. U.S. patent application Ser. No. 08/065,479 Photovoltaic Cogeneration System.) Further, using Thermionic converters to top a Rankine cycle in a cogeneration scheme is also well known. See e.g. "Effectiveness of low-temperature thermionic converters for topping the Rankine cycle", Boris Y. Moizhes (1993 IECEC). Methods a., b., and c. each give a fairly low efficiency of power conversion, while method d. on the one hand has a fairly high efficiency, but on the other is used only for transportation and storage of energy.
None of the above methods have been combined so far, despite the fact each may be made to operate at different temperature ranges, thus opening up the opportunity of creating cogeneration schemes to raise power production system efficiency.